in the past we have been blocked in interoperatability by the use of different frequencies, by the use of different digital formats and been challenged in a number of different ways. i guess since those days there has been one important improvement, one technological improvement, that we use expensively to create interoperatability and that is ip networks built of sdparate systems and the network allows us to operate. as you see from our demonstration as you checked in this morning, as you ridge stered this morning, san francisco talking it oakland, talking to this ship, talking over cellular, talking across and with different networks. the challenge for interoperatability is beginning to be met, i would say, the challenge for interoperatability at the same time is about to get much greater. we as a nation are about to embark on the most ambitous, most challenging communications endeavor that we have ever attempted, which is the creating of purse net, the public safety broad band or 4g network. and with that brings the promise of new challenges for sure in interoperatability and new ca